Scaling of Icing Tests--A Review of Recent Progress

Recent progress in development of scaling methods for icing testing at reduced scale, with the focus on glaze icing, is reviewed. In most glaze icing tests it is now recognized that it is necessary to match test values of an accumulation parameter, of a droplet inertia parameter, and of the freezing fraction at the stagnation point to the values in the reference case. Evidence has been presented in recent years that surface tension effects are also important and must be correctly scaled to obtain valid test results. A Weber number is proposed as an additional scaling parameter for this purpose. It is based on a measure of the thickness of the liquid water flow that exists on the surface of accreting glaze ice. Assessment of the proposed Weber number, using results available in the literature and from purpose-designed tests, suggests that it has merit